GIS stands for Geographic Information Systems. Generally, it is
a computerized sytem that manages spatial information. This spatial
information is mainly comprised of raster data (continuous suface
cover) and vector data (points, lines, and polygons) which serve
as a model for actual physical features such as buildings, roads
or counties. The spatial features may also be dynamically linked
to an attribute database with a varied number of attributes.
Professions/Disciplines that use GIS:
There are many uses of GIS in many proffessional fields and disciplines.
Uses range from proffesional industries such as utilities companies
(power, water, communications, etc.), business marketing, health,
forestry and environmental management, defense, cadastral/ tax assessment,
urban planning, and oil or mineral exploration to name a few. Disciplines
that find uses for GIS may include foresty and environmental studies,
geography, architecture and urban planning, geology, archeaology,
epidemiology and public health, social sciences/ demographics, history,
and business/marketing. Find out more about how these industries/disciplines
use GIS as described by the Environmental Systems Research Institute.
Types of GIS data:
Generally, there are 2 types of spatial data that can be used in
a GIS: vector and raster. Vector data refers to data that contain
features such as points, lines, or polygons. These features are
often used as model to represent actual physical features. For example,
points may represent physical features such as buildings, towns,
hospitals, airports, gas stations, lighthouses, etc. Lines typical
represent features such as roads, highways, streams, rivers, utility
lines, and elevation contours. Polygons typically represent features
such as political boundaries (countries, states, counties, towns,
etc.), structures (building foot prints, industrial plants, football
stadiums, etc.), habitat areas, parks, golf courses, and parcels.
Raster data refers to data that generally contain continuous features
that completely cover an area. Instead of lines, points, and polygons,
rater data is made up of pixels or cells. Common examples of raster
data include air photos, satellite photos, land use/land cover data,
and digital elevation models.
There are a variety of digital formats for GIS vector and raster
data just as there are a variety of GIS software available. See
a table of the most common formats
used in GIS.
To access a more comprehensive dictionary of GIS terms, look at
the AGI GIS